GM's sales rose 24 percent in July, and it's the only U.S. automaker whose market share is up this year, Paul Ballew, GM's chief market analyst, said in a conference call earlier this month.

"It makes perfect sense" to end the program with 2003 models reaching dealer lots, said Dan Poole, vice president of equity research at National City Corp., which owned 260,344 shares of the automaker as of June. Zero-percent loans "can be turned on and off easily," he said.

The world's largest automaker will offer financing of 1.9 percent for 36- and 48-month loans and 2.9 percent for 60-month loans, said Russ Shelton, owner of Shelton Pontiac Buick Inc. in Rochester Hills, Mich. The new plan starts Sept. 4 and runs through the end of the year, he said.

GM spokesman Brian Akre declined to comment on the program change, saying the automaker plans an announcement about incentives next month. Spokeswoman Elaine Redd declined to comment on current inventory levels.

General Motors led automakers in offering no-interest loans after the Sept. 11 attacks, spurring demand at the expense of per-vehicle profit. The company was profitable last year and was better able to trim its vehicle margin than U.S. rivals Ford and Chrysler, which had multibillion-dollar losses last year. The last time General Motors stopped zero-percent loans, its sales fell 12 percent in May.

Ford planned last month to have no-interest loans on a few models, then expanded its program to cover almost all Ford-brand cars and trucks. The Dearborn, Mich.-based automaker last week extended its no-interest loans on 2002 models through Sept. 30.